Bicycle transmission wireless actuation system

ABSTRACT

Bicycle including a frame with a fork, the fork having dropouts between which a wheel axle is mounted. The wheel axle includes a sensor and/or an electric component arranged to be connected to a control element. A detachable electric connection is provided between the sensor and/or electric component and the control element. The detachable electric connection includes a short range wireless connection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Stage of PCT/NL2018/050277, filedApr. 26, 2018, which claims priority to: Netherlands Patent ApplicationNo. 2018801, filed Apr. 27, 2017, the entire contents of each of whichare herein incorporated by reference in their entireties.

FIELD OF THE INVENTION

The invention relates to bicycle transmission actuation systems. More ingeneral the invention relates to bicycle transmissions.

BACKGROUND TO THE INVENTION

Bicycle transmission systems are known. Bicycle transmission system caninclude a gear shifting mechanism. The gear shifting can be discrete orcontinuously variable. In some varieties, a gear shifting mechanism isincluded in or attached to a driven axle of the bicycle. It is known toactuate gear shifting by electronically actuated actuators.Electronically actuated actuators can be cumbersome in that power supplyand/or signal supply needs to be extremely robust and stable to avoidmalfunction of the gear shifting mechanism. Yet in many applicationsweight and or space allowed for electronically actuated actuators and/orpower and/or signal supply is limited. In general supplying power and/orsignals to/from electric components included in or attached to a drivenaxle of a bicycle can be cumbersome.

SUMMARY OF THE INVENTION

It is an object to obviate, or at least diminish, one or more of thedisadvantages mentioned above.

Alternatively, or additionally, it is an object to provide a system fortransmitting power and/or signals to and/or from an electric component,such as an actuator, electric motor, sensor or the like, included in orattached to a wheel axle of a bicycle.

The electric component can e.g. enable gear shifting between a drivercomponent (such as a sprocket, cassette or pulley) and a hub of thewheel axle. Thereto the electric component may require electric powerfor gear shifting of a gear shifting system. The electric component mayalso require a signal for determining a gear shifting direction and/oramount. It is possible that the electric component transmits power or asignal outwardly of the wheel axle.

The wheel axle can be arranged to be detachably mounted to a frame ofthe bicycle. The bicycle can include a frame with one or two forks. Theframe can include a front fork for attachment of a front wheel and/or arear fork for attachment of a rear wheel. The fork(s) include dropouts.For attaching and/or exchanging the wheel a thru-axle (also referred toas through-axle) can be used which can be inserted through the frame (atleast one dropout) and through the wheel axle. Since the electriccomponent is included in or attached to the wheel axle, a detachableelectric coupling is desired between the electric component in or on thewheel axle and a control element and/or power supply element thatusually is placed on or in the frame or the handlebars of the bicycle.

This detachable electric coupling can be formed by a wireless orcontactless connection so that there are no electric contacts that candisconnect because of debris or moisture (water). The wireless orcontactless connection can be a short range wireless connection.

According to an aspect is provided a wheel axle assembly, including awheel axle including a sensor and/or an electric component arranged tobe connected to a control element. A detachable electric connection isprovided between the sensor and/or electric component and the controlelement. The detachable electric connection includes a short rangewireless connection.

According to an aspect is provided a bicycle including a frame with afork, the fork having dropouts between which a wheel axle is mountedwherein the wheel axle includes a sensor and/or an electric componentarranged to be connected to a control element. A detachable electricconnection is provided between the sensor and/or electric component andthe control element. The detachable electric connection includes a shortrange wireless connection.

Optionally, a direct wireless coupling between the electric component inor on the wheel axle and a control element on the handlebars isprovided. This may be difficult to realize since in and around a wheelaxle generally a lot of metal is present that can disturb wirelesssignals.

According to an aspect electric power and/or information is provided tothe electric component in or attached to the wheel axle via acontactless electric coupling.

According to an aspect the thru-axle is used for providing thecontactless electric coupling between the electric component in orattached to the wheel axle and the power supply and/or control element.

Optionally, the thru-axle is provided with a first transmitter fortransmitting electric power and/or signals to the wheel axle. The wheelaxle can be provided with a first receiver for receiving electric powerand/or the signals from the first transmitter. Thereto the thru-axle canbe provided with a first coil as part of the first transmitter and thewheel axle can be provided with a second coil as part of the firstreceiver. It will be appreciated that part of the first transmitter canbe attached to the frame. The first and second coils can be sealedagainst debris and/or water. The first and second coils are positionedsuch that when the thru-axle is inserted in the wheel axle in theposition for securing the wheel in the frame, the first and second coilsare axially positioned relative to each other such that a coupling canbe achieved at high efficiency, e.g. at maximum efficiency. It will beappreciated that the coils will be coupled inductively. However, sincethe inductively coupled coils are able to transmit electric power and/orelectric signals from one coil to the other, the coupling between thecoils is herein also referred to as electric coupling.

Optionally, the first transmitter is wiredly or wirelessly connected tothe control element.

For increasing efficiency of transfer of power and/or signal between thecoils a ferrite layer can be placed adjacent a radially inner side ofthe first coil, a radially outer side of the second coil and/or theaxial sides of the coils.

For increasing efficiency of the transfer of power and/or signal betweenthe coils a middle frequency resonance of the signal on the order of 100kHz can be used over the coils.

According to an aspect, the system is arranged for transferring bothpower and signal between the coils, in one direction or in bothdirections.

According to an aspect a first energy storage element, such as abattery, is included in or attached to the thru-axle. A second energystorage element, such as a battery, can be included in or attached tothe wheel axle. The first energy storage element can be arranged forproviding the first coil with energy. The second energy storage elementcan be arranged for providing the second coil with energy.

Optionally, the first energy storage element has a storage capacity thatis at least ten (10) times the storage capacity of the second energystorage element.

Optionally the system is arranged for charging the second energy storageelement using energy stored in the first energy storage element. Hence,the second energy storage element can be maintained in a state ofsufficient charge. Thereto energy can be transferred from the firstenergy storage element to the second energy storage element via thefirst and second coils.

The system can be arranged for providing energy to an actuator and/orsensor included in or attached to the wheel axle from the second energystorage element. The system can be arranged for providing energy to anactuator and/or sensor included in or attached to the wheel axle fromthe first energy storage element.

The system can be arranged for transferring a signal determining anactuation direction and/or amount for the actuator included in orattached to the wheel axle via the first and second coils. The systemcan be arranged for transferring a signal from the control element (e.g.on the handlebars) to the thru-axle. Signal transfer from the controlelement (e.g. on the handlebars) to the thru-axle can be wireless. Asecond wireless receiver or transceiver can be included in or attachedto the thru-axle. The second transceiver or receiver is herein furtherreferred to as second receiver, nevertheless still covering thepossibility of it being a transceiver. The second wireless receiver canbe mounted to the thru-axle so as to extend outside the wheel axle andoutside the frame to reduce disturbance of wireless communication bymetal parts of the wheel axle and/or frame. The system can be arrangedfor providing the second receiver with electric power from the firstenergy storage element.

It will be appreciated that when exchanging the wheel (and thus thewheel axle), the thru-axle can remain with the frame so that a pairingbetween the control element and the second receiver in/on the thru-axlecan be maintained. Therefore, when exchanging the wheel no time is loston pairing the control element with the replacement wheel.

The pairing of the control element, e.g. of a wireless transmitter ofthe control element, with the second receiver in/on the thru-axle can beperformed, e.g. once when matching the thru-axle with the frame.

It will be appreciated that it suffices to recharge the first energystorage element, e.g. by external charging, e.g. using an electriccharging apparatus. The second energy storage element can be chargedfrom the first energy storage element. Since the first energy storageelement is included in or attached to the thru-axle, it can easily becharged e.g. via a connector on the thru-axle. Charging can be performedwhile leaving the thru-axle in the bicycle or with the thru-axle removedfrom the bicycle. Optionally, the first coil can be used for chargingthe first energy storage element, e.g. via an external charger, e.g.including a third coil.

The system can be arranged such that the first energy storage elementautomatically charges the second energy storage element so that thesecond energy storage element can always provide the actuator withelectric power. In this way also the user never needs to charge orreplace the second energy storage element. This provides a big advantageas the second energy storage element can be difficult to reach since itis mounted in or attached to the wheel axle, and because parts in theneighborhood of the second energy storage element can rotate (e.g. wheelhub and/or driver).

According to an aspect an electric generator is included in or attachedto the wheel axle for charging the second energy storage element. Thegenerator can be driven by rotation of the hub and/or driver.Alternatively, or additionally, the generator can be arranged frogenerating electric energy on the basis of vibrational energy.

Optionally the first energy storage element includes one or more, suchas two, AAAA (LR61) batteries that can be rechargeable and/orreplaceable.

According to an aspect a control unit can be included in or on thethru-axle. The control unit can be arranged for receiving controlsignals from the control element. The control unit can be arranged forconverting input signals received from the control element into signalsto be transmitted to the first receiver. The control unit can bearranged for indicating a current direction and/or current level to betransmitted by the first transmitter to the first receiver.

According to an aspect an actuator control unit is included in orattached to the wheel axle for controlling the actuator of the wheelaxle. The actuator control unit can be arranged for controlling anelectric current direction and/or an electric current amount and/or anelectric current duration to the actuator. The actuator control unit canalso be arranged for controlling a current, e.g. limiting a current tothe actuator.

Optionally, the one or more of the actuator, the actuator control unit,the second coil and the second energy storage element are mounted to abracket 38 that has a hole 40 therein, the bracket forming part of orbeing connected to the wheel axle, e.g., via hole 42 in the axle. Hence,the electronics can easily be mounted to the wheel axle.

Optionally, the first receiver is powered with electric power receivedfrom the first transmitter. Even then, the second energy storage elementcan be present for providing electric power to the electric component,such as the actuator for gear shifting.

Optionally, the first transmitter is mounted to a dropout of the frame.Alternatively, if a rear derailleur is available, the first transmittercan be mounted to the rear derailleur.

The control element can be an electronic switch actuatable with a rotarybutton or push button. Optionally, the electronic switch is arranged tobe actuated via a cable extending from a mechanical switch (shifter),e.g. mounted on the handlebars. Hence, standard mechanical switches(shifters) can be used for actuating the electric component on/in thewheel axle.

Optionally, a connection between the control element, e.g. theelectronic switch, and the first transmitter is a wired or wirelessconnection. The power supply element for power supply of the firsttransmitter can be mounted adjacent to the first transmitter, adjacentto the switch or somewhere in between, e.g. inside the frame of thebicycle.

By using a short range wireless system for the first transmitter andfirst receiver, no pairing of the first transmitter and first receiveris required. Any wheel, with a first receiver, that is placed in theframe can immediately be controlled by the first transmitter and firstreceiver, without a pairing procedure. This can be of great advantagefor a fast wheel exchange.

In case an electrically switching rear derailleur is used, the firsttransmitter of the short range wireless system can be placed close to anelectric component, such as an actuator, of the rear derailleur. In casethe rear derailleur is also actuated wirelessly, a third receiver of therear derailleur can be placed in one housing together with the firsttransmitter of the short range wireless system. A battery used for therear derailleur can then supply power to the third receiver of the rearderailleur, the actuator of the rear derailleur and the firsttransmitter of the short range wireless system. Hence, fewer batteriesare required.

According to an aspect the electric component has only two modes betweenwhich can be switched. The electric actuator can e.g. have only twopositions between which can be switched. Optionally, the component isarranged such that the switching direction is determined by an electriccurrent direction (or voltage polarity) to the component. Hence it canbe possible to switch from one mode to the other by reversing thecurrent direction (or voltage polarity). Hence, a separate controlsignal may not be required for determining the switching direction.

According to an aspect is provided a bicycle including a frame with afork, such as a front form and/or a rear fork, the fork having dropoutsbetween which a wheel axle of a driven wheel is mounted. The wheel axleincludes a switchable transmission between a driver and a wheel hub ofthe wheel. The transmission includes a switching mechanism with anelectric component, such as an actuator, arranged to be actuated by acontrol element that is wiredly or wirelessly connected to the electriccomponent. The electric component can be switched to be in one of twomodes and the control element is arranged for reversing a supply currentdirection to the electric component for switching.

It will be appreciated that any one or more of the above aspects,features and options can be combined. It will be appreciated that anyone of the options described in view of one of the aspects can beapplied equally to any of the other aspects. It will also be clear thatall aspects, features and options described in view of the methods applyequally to the system, device and container, and vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will further be elucidated on the basis of exemplaryembodiments which are represented in a drawing. The exemplaryembodiments are given by way of non-limitative illustration. It is notedthat the figures are only schematic representations of embodiments ofthe invention that are given by way of non-limiting example.

In the drawings:

FIG. 1 shows a schematic representation of a cross sectional view takenthrough a thru-axle of a wheel axle assembly of a bicycle;

FIGS. 2A and 2B show a schematic representations of a cross sectionalviews taken through a thru-axle of a wheel axle assembly of a bicycle;

FIG. 2C shows another schematic representation of a cross sectional viewtaken through a thru-axle of a wheel axle assembly of a bicycle;

FIG. 3 shows a schematic representation of a system;

FIG. 4 shows a schematic representation of a cross sectional view takenthrough a thru-axle of a wheel axle assembly;

FIG. 5 shows a schematic representation of a system;

FIG. 6 shows a schematic representation of a system;

FIG. 7 shows a schematic cross sectional view of a thru-axle in alongitudinal direction;

FIG. 8 shows a detail of the view of FIG. 7 ;

FIG. 9 shows a cross sectional view of a thru-axle; and

FIG. 10 shows a schematic representation of a cross sectional view of awheel axle assembly taken through a thru-axle.

DETAILED DESCRIPTION

FIG. 1 shows a schematic cross section of a wheel axle assembly 1. InFIG. 1 the wheel axle assembly 1 is mounted in a frame 2 of a bicycle301. Here, the wheel axle assembly 1 is mounted between two dropouts 4of the frame 2. The wheel axle assembly includes a thru-axle 6 forsecuring the wheel axle assembly 1 to the frame 2. The thru-axle 6 hereis inserted through the hollow axle 7. The wheel axle assembly includesa hub 8. The wheel axle assembly includes a driver 10 for driving thehub in rotation. Here the driver 10 includes a cassette 12 including aplurality of sprocket gears.

In this example, the driver 10 is connected to the hub 8 via atransmission 14. The transmission is arranged to selectively be in afirst mode and in a second mode. In the first mode a transmission ratioof the transmission 14 is different from a transmission ratio in thesecond mode. Here, in the first mode the transmission ratio is unity(output rotation speed at the hub equals input rotation speed at thedriver). Here, in the second mode the transmission ratio is a speedreduction (output rotation speed at the hub is smaller than the inputrotation speed at the driver). Hence, the transmission can e.g. mimicthe functioning of a front derailleur.

In FIG. 1 the wheel axle assembly includes an electric component 16.Here, the electric component 16 is an electric actuator arranged foractuating the transmission to switch from the first mode to the secondmode and vice versa. The actuator can e.g. include a processor 16A and amotor 16B. It will be appreciated that the electric component can alsoe.g. be a sensor, such as a speed sensor.

For operating the actuator 16 a first receiver 18 is placed in the wheelaxle assembly 1. Here, the receiver 18 is placed within the cassette 10,e.g. near the actuator 16. A first transmitter 20 is placed on the frame2. Here the transmitter 20 is placed at the dropout 4. If the wheelincluding the wheel axle assembly 1 is exchanged the transmitter 20 willremain attached to the frame. Optionally, pairing of the replacementreceiver 18′ of the replacement wheel with the transmitter 20 ca beachieved by use of the thru-axle 6. The thru-axle 6 can include a tag 22that can be read out when placing the thru-axle back in the frame 2. Thetag causes the replacement receiver to be coupled to the transmitter 20on the frame 2.

FIG. 2A shows a schematic cross section of a wheel axle assembly 1. Inthis example, the first transmitter 20 is placed in the thru-axle 6.Here, the receiver 18 is placed within the cassette 10, e.g. near theactuator 16, i.e. on the wheel axle. If the wheel axle assembly, orwheel, is exchanged the transmitter 20 remains with the frame 2 sincethe thru-axle 6 can remain with the frame when exchanging the wheel.Therefore, a pairing between the transmitter 20 and the receiver 18 onlyneeds to be performed once. There is no need for pairing when exchangingthe wheel. It is noted that FIG. 2A shows the thru-axle 6 attached tothe frame, whereas FIG. 2B shows the thru-axle 6 detached from theframe. FIG. 2C shows an example of the first transmitter 20 mounted to arear derailleur 15.

In FIG. 2A, the first transmitter 20 is communicatively coupled, herewiredly, with a second receiver 24. The second receiver 24 is in thisexample arranged for wirelessly receiving a control signal from a secondtransmitter 26. The second transmitter 26 can be associated with amanual input module 27, such as a shifter, for shifting gears. Theshifter 27 can e.g. be mounted on handlebars of the bicycle. The secondtransmitter can be mounted on the handlebars. Referring to FIG. 5 , acontroller 29 can include a processor 25 for processing manual inputfrom the module 27. The controller can include indicator means 23 forindicating a status to the user. Hence a user (rider) can triggertransmission of the control signal by actuating the shifter.Alternatively, or additionally, the control signal transmitted by thesecond transmitter 26 can be automatically generated by a processor,e.g. the processor 25 of the controller 29.

The first transmitter 20 and the second receiver 24 are powered by abattery 28. In this example, the battery 28 is attached to the handle 6Aof the thru-axle 6. It is also possible that the battery 28 is includedin the thru-axle 6, e.g. within the hollow axle 7. It is also possiblethat the thru-axle is wiredly connected to the controller 29 on theframe. Then the second transmitter 26 and second receiver 24 can beomitted. Also, the battery 28 can be omitted in case the firsttransmitter 20 then is powered, e.g. wiredly, from the controller 29(e.g. from a battery 31 of the controller).

The first receiver 18 is here positioned near the electric component 16.As transfer of signals and/or power is effected over a short distance ashort range wireless connection, or first wireless connection, is used,and pairing between the first transmitter 20 and the first receiver 18is not required. The signals and/or power can be transferredcapacitively and/or inductively. A second battery 30, e.g. anultracapacitor, can be connected to the electric component 16. Thisbattery 30 can provide power, e.g. current, to the electric component 16for actuation. The second battery 30 can be charged by the firsttransmitter 20, e.g. using power from the first battery 28. Optionally,the second battery 30 can be used for providing power to the firstreceiver 18. It is also possible that the first receiver 18 is powered,e.g. directly, by the first transmitter 20. It is also possible that theelectric component, e.g. the actuator, is powered, e.g. directly, by thefirst transmitter 20. The second battery 30 can be selected to last theentire life span of the wheel axle assembly 1. Hence, replacement of thesecond battery 30 can be avoided. The first battery 28 can charge, viathe first transmitter 20 and the first receiver 28, the second battery30. Hence, the user only needs to take care that the first battery 28 issufficiently charged. The first battery 28 can be exchangeably mountedto the thru-axle 6 so that it can easily be charged and/or exchanged.

Energy transfer between the first transmitter 20 and the first receiver18 can be in low or mid frequency range. The first transmitter 20 can bea low or mid frequency transmitter. The first receiver 18 can be a lowor mid frequency receiver. FIG. 3 shows an example of a midfrequency,MF, transmitter 20 and midfrequency, MF, receiver 18. In the example ofFIG. 3 the energy storage 30 can be a battery or supercapacitor.Coupling between the transmitter 20 and receiver 18 can be throughcoils. the energy transfer can be arranged to indicate an actuationdirection of the actuator. The receiver 18 can be arranged to wake uponce the first transmitter 20 starts energy transfer. For the wirelessenergy transfer a frequency in the range of 150-300 kHz can be used.This also provides advantages for the electronics used, such asswitching FETs, which only need to be suitable for these relatively lowfrequencies.

Energy transfer can make of two coupled coils. A first coil 32 can beassociated with the first receiver 18 and a second coil 34 can beassociated with the first transmitter 20. The coupled coils can be usedat the resonance frequency of the two coils. At such resonance frequencya good coupling between the coils can be achieved, even if the coils arenot at an optimum position relative to each other. Use can be made offlat coils and/or of concentric coils. The coils allow transfer ofsufficient energy for powering the actuator 16, and optionally thereceiver 18. The coils allow transfer of sufficient energy for directlypowering the actuator 16 without the need for large energy storage inthe exchangeable part of the wheel axle assembly. The coils allow forefficient transfer of signals.

An important aspect is mechanical positioning of the coils. The coilsare arranged to be aligned reproducibly, also when exchanging a wheel.The coils are arranged such that metal parts have a minimum impact onsignal and/or power transmission. In the example of FIG. 4 the secondcoil 34 is housed in a circumferential groove 36 in the thru-axle. Thecoil 34 can be protected from dirt and moisture, e.g. by a suitablepotting or covering. In this example, the first coil 32 is enclosedsurrounding the hollow axle 7. FIG. 8 shows a detailed view of anexample of the second coil 34 in the groove 36. In this example, thecoil 34 is covered with a cover 33. Here the cover 33 is made offerrite. In this example, the coils 34 is housed in a channel shapedinsert 35 in the circumferential groove 36. Here the insert 35 is madeof ferrite.

FIG. 9 shows an example of a cross section of a thru-axle 6. In thisexample, the first battery 28 includes two cells. The second coil 34 isplaced closer to the tip 6T of the thru-axle than in FIG. 4 . FIG. 10shows an example a cross section of a wheel axle assembly 1. In thisexample, the wheel axle assembly includes a thru-axle 6 as shown in FIG.9 . In this example, the first coil 32 is positioned with respect to thehub 8 such that the first coil 32 is concentric with the second coil 34when the thru-axle 6 is mounted to the frame 2 through the hollow axle7. In this example, a center of the first coil 32 substantiallycoincides with a center of the second coil 34.

FIG. 5 shows a schematic example of a system. The manual input module27, e.g. shifter, provides an input to the controller 29. The controller29 generates a control signal to be provided to the first transmitter20. In FIG. 5 the first transmitter 20 is wiredly connected to thecontroller 29. Alternatively it is also possible that the firsttransmitter 20 is wirelessly connected to the controller 29. Then, thecontroller 29 includes, or is connected to, the second transmitter 26and that the second receiver 24 is connected to the first transmitter20, see e.g. FIG. 2 . The second transmitter 26 and second receiver 24can operate on a long range wireless transmission protocol, or a secondwireless connection, such as ANT+, Bluetooth or the like. Thetransmission system of the second transmitter 26 and second receiver 24requires no pairing when exchanging a wheel, as the second transmitter26 and second receiver 24 remain with the frame 2. The second receivercan e.g. be mounted to the thru-axle 6. It will be appreciated that thefirst transmitter/receiver 20 can include, or be associated with acontrol unit. This control unit can be arranged for processing controlsignals from the controller 29. The control unit can be arranged forconverting input signals received from the controller 29 into signals tobe transmitted to the first transmitter/receiver 18. The control unitcan e.g. be arranged for indicating a current direction and/or currentlevel to be transmitted by the first transmitter/receiver 20 to thefirst transmitter/receiver 18. As shown in FIG. 5 , the processor 16A isincluded in or at the wheel axle. The processor 16A is here arranged forcontrolling the motor 16B. The processor 16A unit can be arranged forcontrolling the electric current direction and/or an electric currentamount and/or an electric current duration to the motor. The processor16A can also be arranged for controlling a current, e.g. limiting acurrent to the motor.

FIG. 6 shows a schematic example of a system. Here the controller 29includes the second transmitter 26, here a Bluetooth transmitter. Thecontroller is connected to the manual input module 27, here switches.Thus, in the module A the switch signal is converted to a Bluetoothsignal. The second transmitter 26 is arranged for communicating with thesecond receiver 24. The second receiver transfers control signals to thefirst transmitter 20. Thus, the module B receives a Bluetooth signal andtransmits a power MF signal. The first transmitter 20 transmits controlsignals and/or power to the first receiver 18. Thus, the module Creceives a power MF signal and provides current to the DC motor.

In this example, when the “left” switch is pressed, the actuator motorshould turn clockwise until a mechanical end stop is reached, and whenthe “right” switch is pressed, the actuator motor should turn counterclockwise until a mechanical end stop is reached, or vice versa. Theactuator motor can e.g. be driven at a nominal 3V and 0.3 W.

For the module A, the power Storage A 31 can be a replaceable battery(not necessarily chargeable), for example maximum 1 button cell CR2032(240 mAh, 3V). Preferably the battery life-time allows for at least10.000 switch actions in 1 year, which could equate to approximately 500hrs of biking, at 20 switch actions per hour. The BT Transmitter 26preferably uses Blue Tooth Low energy protocol. The distance to thereceiver 24 is less than 2 m in a normal bicycle. The BT transmitter 26here is arranged to start transmitting a signal at switch input. Pairingof the BT transmitter 26 to the receiver 24 is possible (at closedistance). Preferably secure communication is used between thetransmitter 26 and the receiver 24. The controller 29 can be providedwith a battery charge indication. The battery charge indication can bearranged to be observable on request. The standby power drain should below, therefore, the controller 29 can be arranged to enter a sleep-modewhen the bicycle is not moving. A movement sensor may thereto beincluded. Go to sleep time when no movement or switch activation isdetected can be 5 minutes or more. The go to sleep time can be userselectable. Wake-up time from sleep by movement of the controller ispreferably 1s or less. Preferably, wake-up time by activation of one ormore of the switches is 200 ms or less.

For the module B, the power storage B 28 can be a chargeable battery(not necessarily replaceable). The battery 28 can e.g. include twoAAAA/LR61 Ni-MH cells. FIG. 7 shows an example of two battery cells 28included in the thru-axle 6. The BT Receiver 24 preferably uses BlueTooth Low energy protocol. Battery charge indication is possible, e.g.on request. The charge indication of the battery 28 may be provided tothe user via the controller 29. The module B can be arranged to enter asleep-mode when the bicycle is not moving. A movement sensor may theretobe included. The MF power transmitter 20 can be arranged to starttransmitting MF (100 kHz) power signal on actuation request of one ormore of the switches. The MF transmitter 20 is also arranged to providecharge power to Power Storage C 30 to maintain State-of-Charge ofstorage 30. The module B can e.g. be housed in a sealed box, preferablywater resistant IP67. Charging through a USB or mini-USB cable can beprovided.

For the module C, the power Storage C 30 can be a non-replaceablebattery, such as a capacitor, e.g. mounted on a PCB. The module C caninclude the coil 32, here an NFC coil, and the PCB. The PCB can includethe electronics for the receiver 18 and motor control 16A. Motor controlincludes sending current to the DC motor 16B in the requested rotationdirection. A mechanical end stop detection can be provided by currentfeedback. A current limit and maximum actuation duration can beadjustable. The MF power receiver 18 is arranged to receive a MF (100kHz) power signal and send power to the power storage C 30 and motorcontrol 16A. In an example the PCB can have a full or partial, such ashalf, circle shape, mounted within a enclosure. The enclosure cancontain grease and/or oil.

Herein, the invention is described with reference to specific examplesof embodiments of the invention. It will, however, be evident thatvarious modifications, variations, alternatives and changes may be madetherein, without departing from the essence of the invention. For thepurpose of clarity and a concise description features are describedherein as part of the same or separate embodiments, however, alternativeembodiments having combinations of all or some of the features describedin these separate embodiments are also envisaged and understood to fallwithin the framework of the invention as outlined by the claims. Thespecifications, figures and examples are, accordingly, to be regarded inan illustrative sense rather than in a restrictive sense. The inventionis intended to embrace all alternatives, modifications and variationswhich fall within the spirit and scope of the appended claims. Further,many of the elements that are described are functional entities that maybe implemented as discrete or distributed components or in conjunctionwith other components, in any suitable combination and location.

In the claims, any reference signs placed between parentheses shall notbe construed as limiting the claim. The word ‘comprising’ does notexclude the presence of other features or steps than those listed in aclaim. Furthermore, the words ‘a’ and ‘an’ shall not be construed aslimited to ‘only one’, but instead are used to mean ‘at least one’, anddo not exclude a plurality. The mere fact that certain measures arerecited in mutually different claims does not indicate that acombination of these measures cannot be used to an advantage.

The invention claimed is:
 1. A bicycle including a frame with a fork,the fork having dropouts between which a wheel axle is mounted, thebicycle including a control element, a first transmitter placed at theframe, at or in a rear derailleur, or at a thru-axle, a secondtransmitter included as part of the control element, wherein the wheelaxle includes a first receiver in wireless communication with the firsttransmitter for receiving a signal and/or electrical power from thefirst transmitter and an electric component connected to the firstreceiver for receiving a signal and/or electrical power from the firstreceiver, a second receiver in wireless communication with the secondtransmitter, and wherein the first transmitter is wiredly connected tothe second receiver.
 2. The bicycle according to claim 1, wherein thefirst transmitter is placed at one of the dropouts, or is placed in oron the thru-axle.
 3. The bicycle according to claim 2, wherein nopairing is arranged between the first transmitter and the firstreceiver.
 4. The bicycle according to claim 1, wherein the wheel axleincludes a transmission between a driver and a wheel hub, wherein thetransmission includes a switching mechanism, for switching between afirst transmission ratio and a second transmission ratio, including theelectric component in the form of an actuator.
 5. The bicycle accordingto claim 4, wherein the electric component is configured to be switchedin one of two modes.
 6. The bicycle according to claim 5, wherein theelectric component is arranged to be switched from one mode to the otherby reversing a supply current direction to the electric component.
 7. Abicycle including a frame with a fork, the fork having dropouts betweenwhich a wheel axle is mounted, wherein the wheel axle includes atransmission between a driver and a wheel, wherein the transmissionincludes a switching mechanism, for switching between a firsttransmission ratio and a second transmission ratio, with an electriccomponent arranged to be actuated, wherein the electric component isconfigured to be switched in one of two modes by reversing a supplycurrent direction to the electric component for switching, wherein thewheel axle includes a first receiver connected to the electriccomponent, and wherein a first transmitter is placed at the frame, at orin a rear derailleur, or at a thru-axle, wherein the first transmitteris in wireless communication with the first receiver for transmitting asignal and/or electric power to the electric component via the firstreceiver, the bicycle further including a second receiver wiredlyconnected to the first transmitter, and a second transmitter included aspart of a control element, wherein the second transmitter is in wirelesscommunication with the second receiver.
 8. The bicycle according toclaim 7, wherein the first transmitter is placed at one of the dropouts,or is placed in or on the thru-axle.
 9. The bicycle according to claim8, wherein a second energy storage element provided at the wheel axle isarranged for charging from a first energy storage element provided atthe thru-axle or at the frame, or from a charging device coupled to thethru-axle or to the frame.
 10. The bicycle according to claim 8, whereinthe first transmitter includes a first coil and the first receiverincludes a second coil.
 11. The bicycle according to claim 7, whereinthe second receiver is powered from a first energy storage element atthe thru-axle or at the frame.